/Engine/Source/Runtime/Engine/Classes/Materials/MaterialInterface.h
FGraphEventArray PrecachePSOs ( const TConstArrayView< const [FVertexFactoryType](API\Runtime\RenderCore\FVertexFactoryType) * > & VertexFactoryTypes, const struct [FPSOPrecacheParams](API\Runtime\Engine\FPSOPrecacheParams) & PreCacheParams, [TArray](API\Runtime\Core\Containers\TArray)< FMaterialPSOPrecacheRequestID > & OutMaterialPSORequestIDs )